Patent GB-517050-A (GB)
Title: Improvements in prepayment mechanism for gas meters
IPC: G07F15/02
Filed: 1938-07-30
Abstract: 517,050. Prepayment mechanism for gas meters. KIRKEWHITE METERS, Ltd., and GOLDSPINK, G. E. July 30, 1938, No. 22730. [Class 27] In prepayment mechanism of the kind described in Specification 465,164, which can be set for operation by either of two coins of different sizes and value, e.g., a penny and a shilling, through a two - speed gear, this gear can be set by means of a central control rod when the mechanism is in its zero position so as to be operated by a shilling and is automatically returned to the setting for use with a penny when all the gas paid for is consumed. In the construction shown in Figs. 1 - 3, the worm wheel A can slide on its hollow axle B to 'engage either with the penny worm C or the shilling worm D, a spring A' automatically bringing the penny gear into use when the worm wheel is freed, while the worm wheel is pushed back into the shilling gear position by means of a central control rod L when desired. The worm wheel is locked in either of the positions by an arm G mounted on a shaft G<2>, and having a part G', adapted to engage either the end of a boss E on the worm wheel or a groove F in the boss. The arm G is urged away from the locking position by a spring G<4>, but when a coin has been inserted and the quantity wheel is rotated, another arm G<3> on the shaft G<2> which' engages the quantity wheel is rotated and moves the arm G to the locking position where it is secured by an auxiliary catch P controlled by a spring P<2>. Further movement of the quantity wheel operates the gas-valve slide K<1>, and rocks a bellcrank lever J which releases a main catch H adapted to engage a pin H' on the arm G. At the same time the lever J disengages the auxiliary catch P. When the gas paid for is consumed the valve-closing slide K' rocks the bell-crank lever J to trip the catch H and release the arm G so that the worm wheel, if it is in the shilling position, is returned by the spring A<1> to the other position in readiness for the insertion of a penny. If now it is desired to use a shilling the rod. L is pushed in to move the worm wheel A to the right or low gear position in which it is held by a latch M having a lug M<2> engaging the groove F in the worm wheel hub. When the shilling is inserted and the quantity wheel rotated the arm G is moved to the locking position and held there by the catch H. When the arm G is next released to allow the spring A<1> to return the worm wheel to the penny position, the latch M is simultaneously raised by a link N carried by the arm G and having a hook engaging a pin M' on the latch, so that temporarily the worm wheel is quite free. However, as the arm G and latch move about different centres the link N disengages itself from the latch and allows the latter to fall and lock the worm wheel in its penny position. The lug M<2> on the latch is bevelled so that the worm wheel can move to the right by raising the latch. In a modification the locking arm G is acted upon directly by the bell-crank lever J. 'The coin pocket R is adapted to receive either a penny or a shilling and its base is formed by a lever Q, having an upper position, as shown in Fig. 1, suitable for the insertion of a shilling, and a lower position corresponding' to a penny. The lever Q is connected by springs S<2>, S<3> to levers S, S' operated by collars L', L<2> on the control rod L, so that when the rod is moved to change the gear from the shilling to the penny ratio the springs pull the lever Q down to its lower position. When the rod L is pushed in again to change back to the shilling position a stud S<4> on the levers S, S' moves the lever Q to its upper position. When a shilling is inserted in the pocket the lever Q is pressed down against the action of the springs until it engages the stud S<4>, which forms a stop to prevent a coin larger than a shilling being inserted when the control rod L has set the two-speed gear for a shilling. The action of the springs on the lever Q when a shilling is inserted tends to move the shilling into engagement with the teeth of the quantity wheel.